Signal transmitting means



C. J. FITCH SIGNAL TRANSMITTING MEANS Filed Nov. 11, 1937 5 Sheets-Sheet l ATITCRNEY Aug. 8, 1939. c J, FlTcH 2,168,442

SIGNAL TRANSMITTING MEANS Filed Nov. 11, 1957 3 Sheets-Sheet 2 FIG. 4.

INVENTOR Kfn w ATTO R N EY g- 3, 1939- V c. J. FITCH 2,168,442

S IGNAL TRANSMITTING MEANS Filed Nov. 11, 1937 3 Sheefts-Sheet. 3

ATTORNEY Patented Aug. 8, 1939 PATENT OFFICE 2,1ss,442 SIGNAL TRANSMITTING MEANS Clyde James Fitch, Endicott, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application November 11, 1937, Serial No. 174,019.

4 Claims.

This invention relates to teleprinter transmitting mechanisms and more particularly relates to teleprinters of the type employing power operated mechanisms suitable for actuating the typebars and other parts of the transmitting unit.

It has been proposed to employ electromatic typewriters in various types of known printing telegraph systems; this type of recording unit is operated by means of a constantly rotating roller cooperating with a series of power units, each comprising a cam, the engagement of the cams with the roller being controlled selectively by keys. It also has been proposed to operate permutation bars and /or switch contacts by the cams directly or indirectly to condition the transmitting circuits of the printing telegraph .system. It is well known that it is imperative in such signaling systems to maintain the duration of operation of the controlled contacts as nearly uniform as possible. It is also well known that the recording units of the type just-mentioned employ two types of cams for operation of the machines.

Double lobe cams are used in the said machines to operate the regular typebar mechanisms, and single lobe cams for special machine functions such as carriage return, back space, and tabulating functions. The double lobe cams are arranged to be rotated only a half revolution to operate the associated mechanisms, whereas the single lobe cams are arranged to be rotated a complete revolution to operate the associated mechanisms. Assuming that control contacts are operated or conditioned by all the cams and associated power units either directly or indirectly thereby it becomes evident, in view of the foregoing statements, that the time of duration the said contacts remain operated or conditioned by the power units will vary in accordance with the type of cams employed to condition the control contacts.

It is an object of the present invention to provide means in the transmitting units to obtain equal and uniform time duration of operation of the controlled transmitting contacts irrespective of the type of controlling cam associated with functional mechanisms and controlling keybars. To accomplish this, dummy cam units em- 0 ploying double lobe cams are provided and are arranged to be operated simultaneously with the single lobe cam units controlling the associated functional mechanisms.

Further objects of the instant invention re- 55 side in any novel feature of construction or operation or novel combination of parts present in the embodiment of the invention described and shown in the accompanying drawings whether within or without the scope of the appended claims and irrespective of other specific statements as to the scope of the invention contained herein.

In the drawings:

Fig. 1 is a sectional view of the recording unit.

Fig. 2 is an exploded view of one of the forward bank cam units to show the normal operating position of several of the elements. Certain structural details are exaggerated to show clearly the operating positions of several of the control elements.

Fig. 3 is a perspective view, partly in section, of the carriage return mechanism and part of the keyboard.

Fig. 4 is a sectional view of the transmitting permutation bar mechanism.

Fig. 5 is a detail view of the permutation bar mechanism in operated position.

Figs. 6 and 6--A are a detailed view of the carriage return mechanism or other functional mechanism controlling power unit.

Fig. 7 is a partial sectional view showing the dummy cam unit associated with the carriage return keybar and permutation bar mechanism.

Fig. 8 is a front view of the mechanism shown in Fig. 7.

For illustrative purposes, this invention is shown as embodying a well known type of recording unit, which may be similar in construction to the electromatic typewriter, shown and described in detail in U. S. Patent No. 1,777,055, and hence requires only the following brief description.

Referring to the drawings and particularly to Fig. 1, well known means are provided for actuating the type bars l6, comprising a constantly rotating roller l0, cooperating with a series of individual power units each comprising a cam H, the engagement of the cams with the roller being controlled selectively by the character keybars I'l.

Any suitable means may be provided to rotate the power roller, in the direction indicated by the arrow, which is adapted to cooperate with two rows of cam units arranged in the front and rear of the roller. The cam ll may be provided to be pivoted on one arm of a bell crank lever l2 which is pivoted in the frame of the recording unit, as indicated generally by reference character I3, the other arm of the said bell crank lever is operatively connected with an arm of the bell crank lever ll by means of link It. Another arm of the said lever it is connected to the type bars I l in a well known manner, so as to effect operation of the type bars or any other suitable means connected to the bell crank levers upon selective operation of the controlling keybars ll.

The pivoted bell crank lever I2 is operated by the associated cam ll whenever the latter engages the driven roller; the engagement of the cam with the roller is controlled by means of the associated control keybar il in a manner which will now be briefly described.

Referring now to Fig. 2, the cams occupy normally the positions as shown in this figure, which represents one of the rear bank of the units. In this position theimpeller-arm I2 is urged, by the associated coil spring i9, against one of the impeller-lugs 20, which at the time is in the lower position, and tends to turn the cam II in a clockwise direction. This is prevented, however,

by the engagement of one of the detents 2| on the cam, with the upper stop lug 22 on the stop lever 23. If, however, the corresponding keybar is operated, the bifurcated lower end (Fig. l) of extension arm 24 associated with one of the said keybars ll engages an arm 25 at the upper end of the stop lever 22 which is provided with an offset projection at its end which extends laterally through an opening in the bell crank lever i2. The arm 25 of the stop lever 23 is then swung rearwardly or to the left as viewed in Fig. 1 about the pivot 26 and its lower end forwardly or to the right as viewed in this figure, thus releasing the cam, which'then turns under the influence of the spring urged impeller-arm It. In doing so the upper serrated lobe of the cam is brought into engagement with the power roller. which turns in a counterclockwise direction and therefore causes a continued rolling movement of the cam until the high point has been reached andpassed. This causes the whole cam unit to swing around the pivot I! so as to pull down the corresponding link and actuate one of the type bars or any other mechanism with which the cam unit may be connected.

After the high point of the cam is passed the cam loses contact with the roller, but the said impeller-arm It tends to continue the rotation thereof by engaging the second impeller-lug 2! of cam ll until the second detent 21 engages one of the stop lugs. Since the half rotation of the cam consumes only a small fraction of a second, it is diflicult to release the keybar within this short interval, so that it is the lower lug 28 which is first engaged, but upon the release of the keybar and the return of the stop lever 23 to normal position, this lug 28 disengages the detent, whereupon the impeller-arm rotates the cam slightly, and the said detent then engages the upper stop lug 22.

It is obvious then that depression of a keybar releases the revolubly mounted cam to engage and be actuated by the power roller in turn operating the asociated bell crank lever and its attached links to cause the associated mechanism such as the type bars and other operating mechanisms to-be operated. It is to be understood that an individual cam unit is provided for each type bar or other functional mechanisms associated members and cam rollers.

of the stop lugs, is reversed. For example, if the bifurcated arm 24-11 is positioned to engage the arm 25a at the upper end of stop lever 23-a by virtue of operation of the associated keybar, the said arm is positioned rearwardly or to the left as viewed in Fig. l, and the lower end of the stop lever 23-a is moved forwardly, that is. to the right as viewed in the said figure. This said operation is effective to release the cam, by virtue of positioning the lower stop lug 28-a out of the path of detent 2la, thus permitting the spring-urged impeller arm i8--a to rotate the cam slightly in a clockwise direction to effect engagement of the lower lobe of cam II and power roller. Upon completion of a half revolution of the cam ii, the second detent 2l-a engages flrst the upper stop lug 22a while the stop lever 23-a is in an operated position, but upon release of the associated keybar and the return of the said stop lever to normal position, this lug 22-a disengages the said detent and the impeller-arm rotates the cam slightly so that the said detent then engages the lower stop lug 28-41, as shown in the figure. In this manner the bell crank lever l2a is rotated about the pivot l3-a to operate the associated type bar or any other mechanism associated therewith. For further structural details of the cam units, reference should be made to the above mentioned patent.

In addition thereto the bell crank levers are provided with extension arms 30 (Fig. 4) depending therefrom and on which are rotatably mounted individual cam rollers 3i which are displaced whenever the associated bell crank levers are actuated by the released cams. The cam rollers are positioned so as to be adapted to position or cooperate with selector members 32 whenever the said rollers are displaced for a purpose now to be set forth.

Since the permutation bar unit to be described forms no part of the invention per se, the brief description to follow is deemed sufllcient, for further structural details reference may be made to the copending application Serial No. 113,798, filed December 2, 1936. The signal transmitting unit comprises a plurality of rotatable bars 33, all disposed in the same horizontal plane. The bars :are suitably mounted in end plates secured to the frame of the machine which also are adapted to support the rods 34 which act as guide and supporting rods for the selector members 32.

The said selectors are slidably mounted on the said rods and are adapted to be engaged by the cam rollers 3| to be positioned thereby. Each selector 32 has a plurality of equally spaced studs 35 fixed thereon, three studs on each side of the selector and alternately positioned on each side of the selector. The said studs are'adapted to engage certain of the keys 36, which are suitably secured to the permutation bars 33, when the selectors are displaced by the said extension The keys 36 are arranged to extend above and below the bars 33 as shown in Figs. 4 and 5. The purpose of this arrangement is explained in detail in the said application referred to herelnabove and need not be repeated here. It is sumcient to point out that the keys protruding above the bars are engaged by the studs disposed on the selectors which are displaced or operated by the rear cam units, and the keys extending below the said bars are engaged by the studs on the selectors displaced by the front cam units.

The keys 36 are secured to the associated bars 33 so that the displaced selectors are adapted to displace or partially rotate the said bars when the studs on the selectors engage the corresponding keys. According to the number of keys engaged by the selector studs, various and different combinations of bars 33 are rotated or displaced upon operation of the selectors 32. Fig. 5 shows one of the selector members displaced by the extension member and cam roller associated with one of the front cam units and shows the keys secured to permutation bars numbers 2 to 5 engaged by the selector studs to partially rotate the said bars. Suitable control or switch arms 31 are suitably disposed so as to be released by keys 38 and displaced by the associated springs from their normal position. A group of three switch arms are disposed at each end of the machine; this fact, however, is not of importance and merely a matter of choice. It is seen that the switch arms 31 associated with the permutation bars 33 numbers 2 to 5 are positioned to engage the contacts 40 instead of the normally engaged contacts 39. The contacts correspond to the printer controlled contacts in the known Baudot or combinational code systems and can obviously be included in said printing telegraph systems for control purposes in a manner well known to those skilled in the art. The description just given of one form of control members controlled by the extension members 39 related to controlling indirectly the signal control contacts by means of permutation bar unts, however, it is obvious that groups of contacts can be so disposed as to be engaged directly by the cam rollers 3| when displaced by the controlling bell crank levers and cams. This is a matter of choice and obviously falls within the scope of the present invention.

The description thus far has been limited to mechanisms and control members operated by double lobe cam units. A brief description will now be given of mechanisms of known construction operated by single lobe cams. It was mentioned hereinbefore that such operations as carriage return, back space and tabulating are effected in the electromatic by single lobe cams. It is deemed necessary only to describe briefly one of the functional mechanisms, and for this reason the following description'of only the carriage return mechanism will be given. For further description of this mechanism reference may-be made to U. S. Patent No. 1,753,450.

Referring now to Fig. 3, this mechanism is jointly controlled by a carriage return keybar 4i and a lever 42 pivotally mounted on the rear carriage rail 43. The said keybar controls a single lobe cam unit 44 which is connected by a link 45 to an extension of one of a pair of toggle levers 46. The toggle levers connect a fixed pivot 41 with the upper end of a friction clutch control lever 48. The latter, when pushed to the right by straightening the toggle comprising levers 46, causes a friction clutch 49 to be engaged whereby shaft 50 drives a tape drum 5| as in Patent No. 1,753,450. A. tape 52, wound onthe drum, is connected to the carriage, and as usual operates the line spacing mechanism. Depression of keybar 4! .causes the cam unit 44 tobe operated 'by the power roller, thereby straightening the toggle which looks slightly off dead center to keep the friction clutch engaged while the carriage is returned by the winding of the tape 52 on the drum.

The lever 42 is provided with an inclined cam surface 53 designed to be engaged by a part of the left-hand marginal stop 54 which is adjustably mounted on the usual marginal stop bar 55. A link 56 connects lever 42 to a three-armed lever clutch 49.

51 pivoted on a .xed part of the frame. This lever 5'| is connected by a link 53 to a trip lever 59 pivoted on a boss 59 formed in the frame-work of the machine. One arm of lever 59 underlies the extension of toggle link 46 to whichlink 45 is pivoted.

Near the end of the return movement of the carriage, the lower part of the left-hand marginal stop will strikethe cam surface 53 and depress lever 42 a slight amount. This movement of lever 42 is transmitted by links and 58, and lever 51, to the trip lever 59, rocking thelatter, and by engagement of the arm thereof with the extension of toggle link 46, has the effect ofbending the toggle back through dead center far enough to permit cam unit 44 to assume its normal position and also permits'dlsengagement of The carriage is then arrested in position by lug 5| to commence a new line of writing.

The operation just described is controlled by the power operated cam unit 44 which is afront camunit and comprises a single lobe cam 62 (see Figs. 6 and 6--A). It will be understood from the description hereinabove that the time duration of operation of cam unit 44 must be greater than that of the double lobe cam units for operating the type bars. This increase in operation time of the cam units is obtained by employing a cam 52 having a single lobe and adapted to make a complete revolution each time it is released as compared to the half revolutions of the double lobe cams. For this reason the cam 62 is provided with but a single impellerlug 63 which normally is engaged by the spring urged impeller-arm 64. Likewise, a single detent B5 is provided on the cam 62 and in the normal position shown in Fig. 6 is adapted to engage the lowerstop lug 66 on the stop lever 61. It is evidentnow that upon depression of the carriage return keybar 4| to position the lower'end of the stop lever 61 to the right, thereby releasing the cam 62 by-the disengagement of stop lug 6B and detent 65, that the cam is effective to be rotated a complete revolution by the power roller Ill. Upon completion of the revolution the single detent 65 engages the upper stop-lug 63, and upon operation of the toggle 46 (Fig. 3) upon return ,of thecarriage the stop lever 61 and cam unit 44 are restored to thenormal position shown in Fig. '6. a

Itis understood now that if the selector members 32 (Figs. 4 and 5) were operated by the camunit 44, these members would be operated for a greater length of time than those members operated by the cam units l2 and thereby cause theswitcharms 31 to engage the contacts 40 a greater length of time. contacts in the present day printing telegraph systems would cause many objectionable and unwanted operations. Therefore, it is necessary upon operation of the carriage return cam units or similar functional cam units to provide additional means associated with the carriage return keybar to obtain an operating contact time by its operation equal to the contact time obtained bythe cam units l2.

Referring now to Figs. 7 and 8, the carriage return keybar 4| is shown to be operatively connected by the arm 69, depending from the keybar, to the single lobe cam unit 44 just described, so that upon depression of the keybar the single lobe cam 52 is released to elfect the described function. Secured to the arm 69 is an auxiliary arm Ill extending away from the arm 59 and Operation of the said ll secured to the frame of the unit. The cam unit I! is provided with a double lobe cam ll similar to cams il (Figs. 1. 2 and 4). The cam Ii is released by stop lever II in the same manner as cams ii are released by the associated stop levers. An extension arm is providedwith a cam roller, similar to the extensions III. to engage a corresponding selector member I! of the transmitting unit. The associated selector 3! is displaced upon operation of the said cam and cam unit to operate the contacts ll in a combination corresponding to the combination of permutation bars I! operated by the displaced selector. The cam is rotated a half revolution and then held in an inoperative position by the stop lever ii. In this manner the contacts 4. are operated for a timed interval equal to the operation of the said contacts by the character keybars l1. v

The described operation of the said contacts is obtained even though the cam l2 and cam unit ll are operated for a longer timed interval. The two cams 82 and II are released simultaneously by depression of the keybar ii to release the stop levers l1 and ii, respectively, by the associated controlling arms '69 and II. The cam units are then controlled individually and independently by the associated cams. It has been found that in the described manner the permutation bars and switch contacts are operated so that the duration of contact thereof is practically uniform and suitable for the purposes described hereinabove.

Similar cam units as the units "I2 may be mounted adjacent to the other functional mechanisms and controlled by the associated keybars in a manner as just set forth.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the amass:

invention. It is the intention therefore to be limited only as indicated by the scope of the following, claims.

What is claimed is as follows:

1. In a device of the character described, an operable keybar and associated controlled mechanism. a power operated unit controlled by the keybar to operate the said controlled mechanism, an auxiliary power operated unit, means whereby the said auxiliary unit is. controlled by the said keybar, and signal control means including means whereby the signal control means is controlled by said auxiliary power operated unit.

2. In a device of. the character described, an operable keybar and associated controlled mechanism, a power operated unit controlled by the keybar to operate the said controlled mechanism, an auxiliary power operated unit including means whereby the auxiliary unit is controlled simultaneously with the first mentioned power operated unit by the said keybar, and signal con-- trol means including means whereby the signal control means is controlled by said auxiliary power operated unit.

3. In a device of the character described, an operable keybar and associated controlled mechanism, a power operated unit controlled by the keybar to operate for a predetermined timed interval to operate the said controlled mechanism, an auxiliary power operated unit including means whereby the auxiliary unit is controlled simultaneously with the first mentioned unit by the said keybar to operate for a timed interval less than the said predetermined timed interval,

and signal control means including means whereby the signal control means is controlled by the said auxiliary power operated unit.

4. In a device of the character described, an operable keybar and associated controlled mechanism, a constantly rotating power roller, a power operated unit controlled by the keybar to operate the said controlled mechanism, the said unit including a single lobe cam unit operated by said roller, an auxiliary power operated unit, comprising a double lobe cam unit operated by said roller, said last mentioned unit including means whereby the auxiliary unit is controlled by the said keybar, and signal control means including means whereby the control means is controlled by said auxiliary power operated unit.

. CLYDE J. FITCH. 

